


Filling The Grey's Whites

by emissaryofrainbows



Category: Homestuck, Undertale (Video Game)
Genre: ABDL, Crossover, Diapers, F/M, Farting, Fetish, Gross, Hyper Farting, Weird
Language: English
Status: Completed
Published: 2019-08-02
Updated: 2019-08-02
Packaged: 2020-07-29 12:15:50
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,988
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20082046
Author URL: https://archiveofourown.org/users/emissaryofrainbows/pseuds/emissaryofrainbows
Summary: This story was done as a commission for my good friend Cas. Karkat and Toriel are roommates, but the troll has a pretty severe flatulence problem. They deal with it by putting him in his diaper to keep his farts contained like a giant balloon, but what happens when he unleashes enough gas to fill an entire room?





	Filling The Grey's Whites

**Author's Note:**

  * For [CasFics](https://archiveofourown.org/users/CasFics/gifts).

"Good morning!" a sweet, almost motherly voice said to Karkat. The troll blinked himself awake, forced out of his slumber as the beams of light streaming through his window forced their way into his tired eyes. 

"GOOD MORNING," Karkat said back, in his characteristically aggressive tone while he rubbed the sleep out of his eyes. In all the time they had spent living together, Toriel hadn't failed to be awake before him even once.

"I hope you had a peaceful rest," the goat woman added. The troll nodded. Karkat had in fact had a satisfactory sleep, but you wouldn't be able to tell by his tone, which was as loud and aggressive as ever.

It seemed as though Toriel had already dressed herself in the comfy purple robes she wore on days when she didn't have to work. Karkat's garments were far more eye catching, with one piece of attire in particular being especially unusual. Beneath his grey pants was a conspicuous bulge, one that crinkled audibly whenever Karkat moved.

Karkat Vantas was indeed in diapers. He had a pretty good reason for wearing them, though. Like most other trolls, he was prone to extremely potent gas. To compare it to even the most extreme amounts of flatulence that a human could output would be doing it a vast disservice. It could only be properly likened to hurricanes, tornado, and other such wind-based natural disasters. Karkat's gas was liable to knock items off of countertops on a good day. Most of the time it ended up toppling the furniture itself. While the force was an extreme, dreadful thing to behold, the smell was on an entire other level. Karkat could flood an entire household with stink in a single blast, creating gasses that would linger for hours, perhaps days. Any area tainted by his flatulence would be uninhabitable to anyone not wearing a gas mask. As if the foulness of Karkat's gas wasn't self-evident, the effects it could have on the environment certainly drove the point home. Paint would peel from the wall, flowers would wilt, and windows would steam up. 

Since Toriel didn't want to have to deal with her house nearly getting blown from its foundation every time Karkat had some post butterscotch-pie gas, a solution was proposed. Karkat was to wear diapers for as long as he remained within her home, which would keep his gas contained. So far it had worked fairly well, but it was only a matter of time before something went wrong.

A deep, ominous gurgle was emitted by Karkat's bowels, indicating that he had some morning gas to release. He didn't plan on making much of an attempt to hold it in. That was what his diaper was for, after all. It'd been enough to hold in his gas every previous time, so why would he assume that his padding would fail on him now?

"Oh dear, that sounds like quite the big one," Toriel said.

"YOU THINK?" Karkat said, clutching his arms around his shifting stomach. Even if his diaper could contain it all, it'd still be quite the thing to feel himself letting out.

"You should just let it all out then, dear. It's nothing I haven't dealt with before. 

"I'M TRYING," Karkat snapped back. Despite the troll's best efforts, his gas seemed intent on staying exactly where it was. Toriel spoke up, noticing how much her roommate was struggling. 

"Can I help?" Toriel offered sweetly. 

"HOW ARE YOU GOING TO HELP ME, EXACTLY?" Karkat said, wincing as his bowels began to cramp. Normally his gas erupted out of him whether he wanted it to or not. He couldn't remember the last time he needed to struggle and strain like this to relieve himself. 

"Like this," Toriel said, approaching Karkat with a kind hand outstretched. Though somewhat reluctant, Karkat allowed her to touch him. If whatever she had in mind could help get out this stubborn gas, well, it was at least worth a try.

Toriel began to rub Karkat's subtly swollen belly, applying slight pressure. Not enough to cause him discomfort, but enough to begin to let some of that gas leak out. Karkat huffed, though it did feel rather good.

"Is that better?" Toriel said as she continued to rub. Karkat nodded. Each rub and caress seemed to push him just the slightest bit closer to a point of final relief. He could feel his asshole flexing and puckering, and his bowels beginning to un-cramp.

"YOU SHOULD PROBABLY STAND BACK BEFORE I..."

By time Karkat finished his sentence, it was already too late.

"FUCK!" Karkat said, as his poor asshole spewed a hurricane-like gale of stale, stinking air into his puffy padding. Toriel recoiled as the thudding, thunderous sound exploded into the room. "Oh dear!" she said as Karkat's fart-flooded padding began to rapidly expand like a fluffy white balloon.

BBBBBBBBRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRMMMMMMMMMMMMMMMMMMMMMMMMMVVVVVVVVVVVVVVVVVVRRRRRRRRRRRNNNNNFFFFFFFFFFFFFFFFFFFFRRRRRRBBBBBBBBBBBBBBBLLLLLLL!!!

Karkat's thick padding rendered the sound of his gas muffled and bassy, though it was still plenty loud despite this. Perhaps it was just her imagination, but Toriel could feel the very ground shaking beneath her feet, and the walls of her home rattling. If every there was a fart that could shake a room to its very foundation, it would be this one. Karkat had released some powerful gas in the past, but this one was enough to put all his previous flatulence to shame. 

Luckily, his diaper still seemed to be holding, judging by the absence of any ass-stink floating around the room, though it seemed to be struggling. It swelled massively before Toriel's very eyes as it was filled with a barrage of the troll's farts, until the bloated balloon of padding around his waist was larger than his entire torso. 

"NNNNG, FUCK!" Karkat said. Even compared to his usual abrasive tone, he was shouting at the top of his lungs, just so he could be heard over the roar of his own ceaseless flatulence. "HOW MUCH MORE CAN THERE BE?" he asked, as his ass had still not abated. 

Apparently, there was still plenty. His ass answered his question with a continued torrent of hot, stinking air, as his diaper began to grow to a dangerous size. Toriel was almost starting to regret giving Karkat that beneficial belly rub. Maybe he would've been better off letting himself cramp instead of releasing this huge explosion of flatulence all at once. Regardless of whether or not helping him was the right thing to do before, there was nothing she could do to help him now. All she could do was watch his diaper continue to expand like a hot air balloon, and occasionally take a step back when the diaper started to encroach on her personal space. It looked like it was only a matter of time before she ran out of room to step back into though. At the rate Karkat's diaper was swelling, it looked set to take over the entire room in a matter of minutes.

Karkat's lower body was no longer swaddled by thick, comfortable padding. Now it was surrounded on all sides by a cushion of his own warm air. Mercifully, he could only feel it, and not smell it. Toriel was especially fortunate in this regard. Since she wasn't immune to Karkat's stink as the troll had become, one whiff was liable to knock her out cold. Though the smell did not pose a risk to her, the sheer volume of gas certainly did. She tried to back up to get out of the path of Karkat's expanding diaper, but she found herself backed up against a wall again. She couldn't flee for the next room, for the path there had already been blocked off by Karkat's nappy. She could do nothing but stand there as it continued to grow, the exterior of the padding getting closer with each passing second.

The sound of Karkat's continue fart had not ceased. If anything, it had gotten louder since it first erupted out of ass what felt like hours ago, but was only a meager handful of minutes in the past. Without a doubt, Karkat's screams had increased in volume, in order to be heard above the pervasive crinkling and frrbbrbrbrbbbbrtttttttt-ing.

Despite how vocal he was, he didn't have much to say. He mostly just grunted, questioned why this was happening to him and when it would finally be over. Though Toriel had been passive for most of Karkat's diaper-bloating, his padding was now pressing up against her and slowly forcing her up against the wall. The swell of Karkat's diaper pressed up against her chest. Now that she was so close to it, it really did feel like an overinflated balloon. She even picked up a whiff of Karkat's butt stink, which had begun leaking out of the pores of the padding. Luckily, the brunt of the stench was contained. Toriel didn't want to think what would happen if she were exposed to all those pent-up farts at once.

"Oh dear," Toriel said, as the diaper pushed her harder against the wall. It looked like there wasn't much more room left for it to expand, she could barely see Karkat any more with the ocean of fart-filled padding between him and her. "If you are able to stop, now would be a good time..."

"YOU THINK I'M NOT TRYING?" Karkat said. Indeed, the troll had been trying and failing to clench his asshole shut, but the force of the wind rushing out of him was far greater than that of his sphincter muscles. It seemed like his diaper was set to burst if it continued on the path it was on. But that simply couldn't be allowed to happen. An ass eruption of that size would render the immediate area inhospitable for weeks. 

Still, Toriel's words convinced him to try perhaps just a little bit harder. With some exertion, he was finally able to clench his asshole shut, but the damage to his diaper had already been done. There wasn't a single corner of the room that his poot puffed padding was not pressed up against. The walls creaked dangerously, threatening to collapse under the pressure. The diaper itself seemed to be holding just fine though, containing Karkat's massive fart bomb admirably with only the occasional stink particle slipping out. There weren't any tears or weak points in the padding to speak of.

The troll panted with exhaustion. Now that he no longer had to worry about his own out of control ass, he immediately went to look around the room for where his friend had gone. Karkat couldn't see where Toriel was, but he could hear her muffled voice as she cried out from beneath a mountain of smothering diaper fluff. She could tell that Karkat's fart had finally ceased from the sound, now that the room was no longer filled with the roaring din of his ass uncontrollably spewing its gaseous contents and the crinkling that followed.

"I'm over here," Toriel said in a measured tone, never one to make too much of a fuss. 

"SORRY ABOUT THAT," Karkat said, feeling fairly embarrassed. He hadn't felt ashamed about any of the bombastic farts he'd unleashed prior to this, but none of them had ended up quite so disastrous for Toriel and her home. 

"Oh, you don't need to apologize," Toriel said, as she tried to escape Karkat's padding like a dog trying to wriggle out from underneath a blanket. "I think everything went pretty well considering."

Karkat had to agree. Though things had been bad, they certainly could've turned out much, much worse. Still, that wouldn't make Toriel's escape any easier. Karkat could feel her wriggling vibrating through the whole of his room-sized diaper.

"I suppose there's just the matter of changing you and getting rid of that thing. That will certainly be a challenge."

Toriel was right. Perhaps the hardest part was yet to come.


End file.
